Heater apparatus



Nov. 21, 1939. L. p. SOULE HEATER APPARATUS 2 Sheets-Sheet 1 Fi led March 8, 1932 Q n o o o o o o v l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l I l l l l ||.l W A 2 5 u H l H o l m o l H. o l r. v 4 4| 2 Mal I 5 s e w b u o m m w W H 0 M il l n o l {will ll 1 l l I l l l 1 l l l I l l l l l l l l 1 l l I l l l l I l l I l l I l l l l l i I l l l l l l l l l l l l l l l l l J o o o o o o m INVENTOR LAWRENCE C; SouLE,

. A'ITORNEY Nov. 21, 1939.

L. C. SQULE HEATER APPARATUS 7 Filed Marbh 8, 1932 2 sheets sheei )INVENTOR .f LAWRENCE 6. SOULE,

- ATrbRNE Y Patented Nov. 21, 1939 HEATER APPARATUS LawrenceC. Sonic, Essex Fells, N. 3., assignor, by

assignments,

toCan-i er Corporation,

Newark, N. 1., a corporation of Delaware Application March 8, 1932, Serial No. 597,519

1 Claim. This invention relates to heat exchange devices employed, more particularly, for heating or cooling air. The general type of heat exchanger to which this invention is directed usually comprises 5 a series of tubes for the passage of steam or other temperature affecting medium, preferably provided with fins or plates to increase the radiating surface thereof, and one or more headers to which the tubes may be attached, and by which the steam or other medium may be introduced to and withdrawn from said tubes. Heat exchange devices of this type are widely used in heating and air conditioning systems for buildings and other enclosures in which temperatures are usually controlled by varying the amount of steam or other conditioning medium admited to-the device. While such heat exchange device may be employed-as a built-in component of a heatingor air conditioning system, it is often desirable to have the devices constructed in the form. of individual unitary heating and/or cooling units. Due to the great heat conductivity of the metal, and more particularly of the tubes, contained in such units, and because of sudden and wide changes in temperature to which the units are frequently exposed, and because the require ments of heating or air conditioning often de mand the metal and tubes of the unit to be subjected to a wide range of temperatures, it follows 30 that great strains and stresses are set up in the tubes and in the heaters to which they are at- I tached, due to the consequent large expansion and Another object of the invention is to provide 1 40 means for spacing the tubes relatively close together, at the same time providing ample working space at the points of connection with the headers. J 1; i

Afurther object of the invention is to provide as means for positively draining any condensate formed in the tubes, without necessitating tilting'the casing containing the tubes. A feature of the invention-resides in providinga tube with a bend therein adapted to com- 60 pensate for heating and'cooling stresses, as'well as to provide for drainage, at one end ofthe tube. The structure enables the application ofthis feature to tubes of varying length by the same operation. g 55 A further feature resides in reducing the size of the tubes at their extremities, so that the radiating portion of the tubes may be spaced relatively close together and yet provide ample and accessible working space at the points of connection of the tubes and header.

Another feature is that the reduction of the size of the tubes at their extremities eliminates the necessity for providing individual orifice rings for the tubes, the smaller opening provided by the reduction in size of the tube serving as an ori- 10 iice so that equal distribution of steam pressure to all the tubes will be assured. Further objects and features of the invention, making for efliciency in operation and advantages and economy in design and assembly will be more 16 apparent from the following description of an illustrative form of the invention to be read in connection with the accompanying drawings, in which: 7

Fig. 1 is a. plan view of a unit incorporating the go invention with some parts partly broken away,

Fig. 2 is a fragmentaryview of a portion of a" header used in connection with the unit .illustrated in Fig. 1,

Fig. 3 is a fragmentary view, partly in section, 25 cf'an assembly of 'tube connections at a header,

Fig. 4 is a side elevation of the unit shown in Fig, 1, and 1 Fig. 5 is "a plan view of a section of radiating tubing of a type preferably employed.

Referring 'to the drawings, similar designa tions referring to similar parts, the heat exchange device illustrated comprises an inlet header 6 and an outlet header I, connected by entering headefi from a supply pipe connected to the header at '9 will pass through the several tubes, into outlet header use then leave the unit through a suitable discharge line at discharge connection -II. The headers maybe constructed reduced in diameterat their extremities, as indicated at I: in Figs. 1, a and 4, The nuts. I: are placed on the contracted or reduced ends of tubes ,as shown Fig. 3. 'The end of the tube is 55.

then re-expanded to assume a frusto-conical shape, so that when a nut I3 is screwed on its corresponding nipple II, the end of the tube will be firmly and securely pressed between the inner shoulder of the nut and the end of the nipple, as illustrated, thereby forming a vapor-tight joint. If'desired, the tube could be welded to the header .or couldbe fastened to a suitable nipple by joinder as disclosed, for example, in Patent No. 1,770,852.

Each tube 8 is bent at ll, as illustrated in Fig. 4, a predetermined distance from one extremity thereof, and is again bent at l5. All the tubes are similarly bent at points I I and I5 and the bends are usually at predetermined identical distances from one end of the tube, although, if desired, the bends in different tubes may be variously positioned. As illustrated in Fig. 4, each point on the lower tube 8 may be considered in a plane substantially parallel to a plane containing a corresponding point on the upper tube. Although the illustration shows two coils, one above the other, in a vertical plane, it is apparent that any number of coils may be similarly positioned above one another in a vertical plane, and, as

illustrated in Fig. 1, the number of such series of coils is limited only by the size of the unit or casing containing them. The bends at points I4 and I5 should not be sharp. In fact, it is un desirable to have sharp angle or short radius bends.

where the device is used for condensing vapor, such as steam, and is installed in a horizontal reduced substantially before it reaches bend i5 7 In shaping the tubes, the bends l4 and I Swill be positioned in each case at the same distance from one end of the tube and all tubes, regardless of their lengths, may, therefore, be subjected to the same bending operation, since the length of tubes for diiIerent size heaters may be increased merely by increasing the distance from the bend [5 to the inlet end of the tube at the point it meets the connection at the inlet header. It will be noted from Fig. 4 that the bends ll are placed relatively close to the discharge header 1. In practice, the bend is formed just as close to the discharge end of the tubes as is practicable without interfering with the ability of the bends to absorb contraction and expansion. Thus, the

discharge end portions of the tubes are relatively short, or the bends are formed a minimum distance from the discharge headers Bends l4 and I5 serve a double purpose. First, any expansion or contraction in the tubes will be taken up, due to this bent construction, without placing undue stress or strain on the headers or on the connections to the headers. Furthermore, differences in temperature of individual tubes will be of no consequence, since each tube is free to expand and contract independently. Second,

position, some means must be provided for draining. condensate to the discharge header; and the bends provided" herein accomplish this result. Usually, such drainage has been eflected by tilting the whole heater. However, by bending the tubes, as illustrated, draining is automatically carried on in: simple and trouble-proof fashion. It is obvious that the steam pressure will not be from inletheader 6 and that condensation, it any, will take place beyond said point. Gravity itself would then be sumcient to bring about required\ drainage. However, the velocityg of the flowing steam-will aid gravitation in assuring complete drainage of condensate. Thus, the unit.

in flat position, will be self-draining. By flat,

position is meant one in which vertical is employed through the casing.

The bending of the tubes at two points measured from the discharge ends of the tubes also serves a double purpose. First, it makes possible the bending of all tubes for all sized exchangers the device is used for condensing steam, it is evident that the quantity of steam condensed will depend upon the heat load. Thus, when the steam is first turned on, excess quantities of condensate will be formed. It is not unusual in such cases for the heater to become water logged, i. e., the discharge headers and a portion of the tubes filled with condensate, due to the inability of the discharge line to carry ofl condensate at a sufliciently great rate. Obviously, any portion of the tubes which are water logged are out of service so far as condensing steamis concerned. In applicants device, if the header 1 is completely filled, it is evident that only the short end portions, and a small part -oi the bent portions, of the tubes, will be out of service, while the remaining, and much greater part of the tubes is clear and useful.

By reducing the diameter of the. tubes at I 2, it is possible to space the radiating portion of the tubes closer together than would be the case if the tube ends were of the same diameter as the body portions of the tubes. As may be noted in Figs. 3 and 4, the spacing of the radiating portions of the tubes insuresmaximum radiation and permits interfltting of radiating surface, so that air passing through the heater will contact, to a maximum degree with the radiating surface. The reduction in tube end diameter, however, leaves ample working space at the ends of the tubes so that nuts l3, for example, may be easily. reached for disassembly and repair, if necessary; and this spacing between endsis made possible, even though there is relatively no similar spacing between the radiating or body portions of the tubes themselves. f

In heat exchange devices of this type, in which steam isemployed, an orifice ring or similar device is usually placed in the ends of the tubes.

tion .to supplying advantages in assemblyand enabling the packing of more radiating surface in' a given casing also provides orifices for the tubes, so that the steam fed to each will be at substantially equal pressure.

The supply and'discharge connections 9 and I8 are suitably fitted within support plates'li which may be welded or otherwise fastenedto headers 6 and 7 respectively. The plates Ii are provided with a number of holes l1 through which bolts or the,like may be fitted to secure the device within a protective casing 20. The casing may be of any desired type, such as that shown in Fig. 1 for retaining a header and tubes in an encasement. Cover plates 2| are suitably fastened to support plate l6 and serve substantially to enclose the header, fittings. and reduced'portions of tubes 8. As a-result, airpassing through the device will not be able to bypassany of the radiating surface, since the cover plates will force the air to pass through the extended radiating surface alone.

Supply and discharge connections or-flttings 9 and III, at opposite ends of the casing 20, are preferably located equidistant from the'sides oi? the casing. This is an advantage in mounting the casing where supply and discharge-pipes are in line and alsoenables the casing to give on both sides of the supply and discharge fittings if stresses should arise during assembly of the \mit or while it is being installed. In practice, the

ofiset, i. e., the distance between the center lines of the straight-tube portions, isfive inches, or a comparatively small percentage of the length. of the casing. 'The width of the casing is, therefore, held within practical limits, even 'th'ough applicants double bend feature, and mode of assembly, is employed. Thus, the manner of assembling-the casing, plus the character of the bent tubes make'for flexibility instead of rigidity, so that breaks or distortion arising from stresses incident toinstallation or operation are substantially eliminated.

'fo prevent'bypassing of air around the tubes, the casing 20 is preferably provided with baflles Since certain changes -may be made in the above construction and diiferent embodiments of the invention could-be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and not in a limiting Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

' In a heat exchanger a casing, headers mounted at opposite ends of said casing, a plurality of bent heat radiating tubes having reduced end portions joining said headers, said tubes being bent at two zpoints relatively close together and at predetermined distances from one end of the tubes, said tubes being mounted on said headers so that the headers are at different elevations when the casing is in horizontal position, and plates on said casing for covering the headers and the reduced end portions of the tubes.

LAWRENCE C. SOUL-E. 

